Designed and mass-manufactured 50 light-up, injection-molded yo-yos inspired by Boston's iconic CITGO sign.

Objective. In 2.008 (Design and Manufacturing II), I worked in a team of five undergraduates to design and manufacture 50 plastic yo-yos over the course of the semester.

Solution. Taking inspiration from the CITGO sign in Boston, my team designed the yo-yos below.

The yo-yo has six main components: the injection-molded body, a red transparent pyramid, a PCB, blue thermoformed letters, a white cover, and a press-fit outer rim. The internal PCB houses a button, battery, and LED, illuminating the transparent pyramid from behind — the pyramid doubles as the button, toggling the LED on and off.

I was responsible for the yo-yo body, which houses all the electronics and components. Sizing its depth was a challenge — accounting for button-travel height and injection-molding defects — as was ensuring the rim press-fit with the body despite shrinkage, which required multiple runs to assess process inconsistencies.

I designed the aluminum molds in Autodesk Fusion and machined the tooling on the HAAS CNC. I also helped thermoform the letters and punch out features with a die. Most manufacturing took place at MIT's Laboratory for Manufacturing and Productivity (LMP).